In order to facilitate the examination of internal body cavities with an external orifice, it is sometimes necessary to employ an instrument to dilate the orifice in order to see into the cavity. Such instruments are called specula. Specula for examination of the cervix employ a pair of paddles or blades which are inserted into the vagina. The paddles are then separated to dilate the vaginal orifice and permit examination of the cervix.
It is extremely useful to illuminate the interior of the cavity being examined with a speculum in order to facilitate examination. The prior art has relied on light sources mounted on the speculum or supported separately from the speculum and arranged to direct light into the cavity being examined. Such light sources are expensive, clumsy and difficult to integrate into single-use, throw away disposable specula. One prior art patent, W. C. Moore et al U.S. Pat. No. 3,716,047, granted Feb. 13, 1973, discloses a speculum with a curved light bar within one of the paddles of the speculum which guides light, by internal reflection, from a light source in the handle, toward the cavity being examined. Such a guided light illumination means adds significantly to the cost of the speculum as well as increasing its size and weight. Moreover, the accommodation of a light source detracts from the disposable nature of the balance of the speculum.